I met Tom,under his arm there was a book.

I met Tom who under his arm there was a book.

I met Tom,under his arm there was a book under his arm

1.两句句子之间需要一个连词来连接
2.在他手臂下不能用BELOW
When i met tom, there was a book below his arm
I met Tom,and below his arm there was a book.
thank you.

I met Tom, there was a book under his arm